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(No Model.) 4 Sheets-Sheet l.

E. H. JOHNSON & E. T. GREENPIBLD. WIRING STRUCTURES ECR ELECTRIC LIGHTING.

No. 401,498. Patented Apr. 16, 1889.

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(No Model.) 4 Sheets-Sheet 2.

E. H. JOHNSON & E. T. GREENFIELD. WIRIIICr STRUCTURES ECR ELECTRIC LICETINC.

No. 401,498. Patented Apr. 16, 1889.

(No Mdem 4 sheets-sheet 3.

E. H. JOHNSON-8u E. T. GREENFIELD. WIRING STRUCTURES TCR RLRCTRIC LICIITINC.

110,401,498. Patented Apr. 16, 1889.

(No Model.) 4 sheets-sheet 4.

E.V H. JOHNSON & E. T. GREENPIBLD. WIRING STRUCTURES IOR RLRGTRIG LIGHTING.

No. 401,498. Patented Apr. 16, 1889.

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UNITED STATES PATENT OEEIcE.

EDIVARD H. JOHNSON AND EDIVIN T. GREENFIELD, OF NEV YORK, N. Y.

WIRING STRUCTURES FOR ELECTRIC LIGHTING.

SPECIFICATION forming part of Letters Patent No. 401,498, dated April 16, 1889.

Application iled September 2l, 1888. Serial No.285,997. (No model.)

To all whom t may concern:

Be it known that we, EDWARD ll. JOHNSON and EowiN T. GREENEIELD, both of New York city, in the county and State of New York, have invented a certain new and useful Iniprovement in Wiring Structures for Electric Lights, of which the followingl is a specification.

The object ot our invention is to enable houses and other structures to be readily provided with wires for electriclight-ing and to enable any wire in a building to be readily removed and replaced by another when necessary, and also to furnish protection from nre due to crosses or leakage, on the wires.

In carrying our invention into effect we place the conductors in pipes or conduits made of insulating material., through which pipes the wires extend to the points where they are to be conneetcdwith iixtures orelectric lamps. Preferably the structure is provided with a complete system of such pipes or conduits extending continuously to every place where an outlet is required, the pipes being all joined together .through suitable junct-ion-boxes, which gives access to each pipe atits extremity. This enables us, when the building is to be wired, to very readily and conveniently run the wires by fishing them through each pipe from the junctioirbox to the outlet; and, further, it enables us, whenever a wire becomes damaged or its insulation deteriorated in any way, to readily disconnect such wire and withdraw it and put another in its place without disturbing any of the other wires or other details ot' the building.

IVe employ for our conductors within the pipes two wires placed in close'proxiniity by twisting them together, the wires being insulated i'rom each other and the two wires fornr ing opposite sides of the circuit. At the junction-boxes and at all points where the ires branch we interpolate fusible links or safety catches therein. One object ot' confining the wires in close proximity is to make certain the operation of the safety-catches. When a leak occurs between. the two sides of a circuit, it is intended that the safety-catches shall give way at once; but in practice with the or dinary arrangements this often does not ocour, for leaks sometimes occur which are ot i too high resistance to cause such low of current as will i'use the safety-catches, but are still suiicient to cause danger from lire; but by placing the wires close together any slight leak immediately increases in extent and causes a short circuit of low resistance, which at once causes the safety-catches to give way. In addition, no serious lire can occur in the coniined space within the tubes, for any combustion will be smothered by the lack of air and draft. The wires being protected from mechanical in j ury and from contact with dustor other foreign materials, and the pipes being of insulating material, the chances of the occurrence ot a leak are very slight, and if; any leak does occur the circuit is at once broken by the safety catches, whereby the most complete immunity .troni danger of iire is insured.

Our invention is illustrated in the accompanying drawings. Figure l is a longitudinal section of an ordinary house, illustrating the general arrangement of the pipes 5 Fig. 2, a plan view showing the pipes in the cellar or basement of the building. Fig. 3 illustrates the arrangement of a pipe within a room. Fig. e is an enlarged view, partly in elevation and partly in longitudinal section, of a line oi' pipe, illustrating the joints and elbows and the peculiar fishing-wire which we prefer to employ. Fig. 5 is a vertical section of a junction-box with its two halves separated, and Fig. G a top view of the lower half of the box.

A main junction-box, A, is placed at a convenient point, usually in the basement or cellar of the building. A pipe, B, ext-ends from this box to the front et the house. From the openings in the junctioubof: A number of pipes, C C, radiate to different parts of the building, and are joined to vert-ical pipes or risers D D, which extend up through the house, and have on each floor a junction-box, E, from which branch pipes F l? extend to outlets G G.

The junction-boxes are all preferably of the construction illustrated vin Figs. 5 and 6, each consisting of two cylindrical halves, H H", the upper halt fitting intovthe lower half, and each half being provided with notches a a, which form circular pipebpenings when the two halves are placed. together. The

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that of the pipes.

boxes are made of metal or other suitable material. A block, b, of wood'or other suitable insulating material, is set in the bottom of the box, and on this block are fixed two metal rings, c c', or other contact-plates for making multiple-arc electrical connections within the box.

All the pipes B, C, D, and F are made as small and light as possible. We make them of insulating material, and preferably of thick paper or pasteboard, which is. impregnated with a suitable moisture-proof and non-infiammable paint or compound.

The pipes D and F we prefer to place under the plaster of the walls or partitions of the house, securing them to the studding or elsewhere by ordinary double-pointed staples` d, Fig. 3. The junction-boxes E are also secured to the studding, and their upper halves or covers project outside of the line of the plaster, which is indicated by the dotted line in Fig. 3.

Where two lengths of pipe are to be joined, we prefer to employ coupling` devices l I for this purpose.` These consist each of a spunmetal sleeve, e, made flaring at both ends, and beveled split bushings f f. The bushings ff being placed on the ends of the pipes to be joined, such ends are inserted in the sleeve e, and the bushings, being then grasped by a suitable tool, are forced as tightly as possible into the sleeve, whereby the sleeve is wedged upon the pipes and the same are tightly secured together. This furnishes a secure joint, and one which has no inwardly-extending edges or projections to catch the wire and obstruct its passage through the pipe.

For bringing the pipes around corners, We provide elbows K, preferably made of insulating material, which may be the same as le makel these elbows with as wide a curve as possible to make the passage of the wires through them as easy as possible, and with straight extremities of sufcient length to enable them to be readily coupled in line with the straight pipes.

-The system of pipes will in new buildings be putin position before the plaster is put on. Where old buildings are to be wired, the same methods are followed as in providing buildings with gas or other pipes.

In Fig. 3, D may represent a vertical riser, and E a j unction-box in the uppermost story of the house, while F is a pipe extending up the wall and across the ceiling to the middle of the room, where an'elbow is placed, proconsists of a core, m, of steel wire wound spirally over its whole length with 'another wire. An eye, o, is formed at one end, and a weight, p, may be placed at the other. Now, if it is desired to run a wire from the main box to a rstfstory junction-box, the latter is opened and the iishing wire is inserted into the vertical pipe D and 'passed through it into pipe C, and so on to the box A, the end having the eye o entering said box and the other end projecting at box E. The conductingwire is then hooked to the eye o, and so is drawn up through the pipes to box E. In a similar way the wires are run through the branch pipes F tothe various outlets, the iishing-wire being first passed through the pipe in whatever direction is more convenient, and the conducting-wire then attached to it and drawn through the pipe. The peculiar fishing-wire which we employ is stiff enough to be pushed readily through the pipes and flexible enough to pass around the elbows without difliculty.

For the conductors which are placed in the tube We prefer to use the ordinary iiexible cord-that is, two iiexible conductors twisted together and in a common braided retainingcovering, each wire forming one side of the circuit.

The wires being placed in the pipes, the connections are made in the j unction-boxes. This may be conveniently done, as shown'in Fig. 6, all the positive wires being joined to one of the rings c c and all the negative Wires to the other. Fusible safety-catches o r are interpolated, preferably, in each side of each circuit within the junction -box, and thus safety-catches are provided for each outlet, which makes it unnecessary in most cases to provide safety-catches in the fixtures. The

lsafety-catches in the junction-boxes are readily accessible and can easily be replaced when destroyed.

lf at any time any one conductor extending froln a junction-box to an outlet becomes deteriorated or damaged, such wire can readily be removed by disconnecting it at both ends and drawing it out of the pipe, and another wire can with great readiness be fishedV bination,'with the building or structure, of a system of insulating-pipes extending throughout the same, and comprising main and branch pipes, a pair of wires in each pipe, insulated from each other and placed in close proximity j The wires twisted together are illusv trated in Figs. 5 and 6 of the drawings.

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to each other, and each forming one side of an electric-lighting circuit, an d safety-catches interpolated -in the circuit, substantially as set forth.

3. In house-Wiring for electric light, the combination of a pipe of insulating material, a `pair of insulated Wires twisted together Within said pipe, each wire forming one side of an electric-lighting circuit, and a safety-catch interpolated in said circuit, substantially as set forth.

il. ln house-Wiring for electric light, the coinbination, With the building or structure, of a system of pipes extending throughout the structure,comprising main pipes, branch pipes extending from said main pipes continuously to all points Where outlets are required, junction-boxes connecting the branch pipes to the main pipes, a pair of Wires placed loosely in EDVD. H. JOHNSON'. EDWIN T. GREENFIELD.

Witnesses:

WILLIAM PELZER, A.. W. KIDDLE. 

